In multicellular organisms, homeostasis is maintained by balancing the rate of cell proliferation against the rate of cell death. Cell proliferation is influenced by numerous growth factors and the expression of proto-oncogenes, which typically encourage progression through the cell cycle. In contrast, numerous events, including the expression of tumor suppressor genes, can lead to an arrest of cellular proliferation.
In differentiated cells, a particular type of cell death called apoptosis occurs when an internal suicide program is activated. This program can be initiated by a variety of external signals as well as signals that are generated within the cell in response to, for example, genetic damage. For many years, the magnitude of apoptotic cell death was not appreciated because the dying cells are quickly eliminated by phagocytes, without an inflammatory response.
The mechanisms that mediate apoptosis have been intensively studied. These mechanisms involve the activation of endogenous proteases, loss of mitochondrial function, and structural changes such as disruption of the cytoskeleton, cell shrinkage, membrane blebbing, and nuclear condensation due to degradation of DNA. The various signals that trigger apoptosis are thought to bring about these events by converging on a common cell death pathway that is regulated by the expression of genes that are highly conserved from worms, such as C. elegans, to humans. In fact, invertebrate model systems have been invaluable tools in identifying and characterizing the genes that control apoptosis. Through the study of invertebrates and more evolved animals, numerous genes that are associated with cell death have been identified, but the way in which their products interact to execute the apoptotic program is poorly understood.
Caspases, a class of proteins central to the apoptotic program, are cysteine protease having specificity for aspartate at the substrate cleavage site. These proteases are primarily responsible for the degradation of cellular proteins that lead to the morphological changes seen in cells undergoing apoptosis. For example, one of the caspases identified in humans was previously known as the interleukin-1xcex2(IL-1xcex2) converting enzyme (ICE), a cysteine protease responsible for the processing of pro-IL-1xcex2 to the active cytokine. Overexpression of ICE in Rat-1 fibroblasts induces apoptosis (Miura et al., Cell 75:653 [1993]).
Many caspases and proteins that interact with caspases possess domains of about 60 amino acids called a caspase recruitment domain (CARD). Hofmann et al. (TIBS 22:155 [1997]) and others have postulated that certain apoptotic proteins bind to each other via their CARDs and that different subtypes of CARDs may confer binding specificity, regulating the activity of various caspases, for example.
The functional significance of CARDs have been demonstrated in recent publications. Duan et al. (Nature 385:86 [1997]) showed that deleting the CARD at the N-terminus of RAIDD, a newly identified protein involved in apoptosis, abolished the ability of RAIDD to bind to caspases. In addition, Li et al. (Cell 91:479 [1997]) showed that the N-terminal 97 amino acids of apoptotic protease activating factor-1 (Apaf-1) was sufficient to confer caspase-9-binding ability. Inohara et al. (J. Biol. Chem. 273:12296-12300, 1998) showed that Apaf-1 can bind several other caspases such as caspase-4 and caspase-8. Apaf-1 can interact with caspases via CARD-CARD interaction (Li et al., supra, Hu et al., PNAS, 95:4386-4391, 1998).
The present invention is based, at least in part, on the discovery of genes encoding CARD-3 and CARD-4. The CARD-4 gene can express a long transcript that encodes CARD-4L or a short transcript that encodes partial CARD-4S. CARD-3 and CARD-4L/S are intracellular proteins that are predicted to be involved in regulating caspase activation.
The CARD-3 cDNA described below (SEQ ID NO:1) has a 1620 open reading frame (nucleotides 214 to 1833 of SEQ ID NO:1; SEQ ID NO:3) which encodes a 540 amino acid protein (SEQ ID NO:2). CARD-3 contains a kinase domain which extends from amino acid 1 to amino acid 300 of SEQ ID NO:2; SEQ ID NO:4, followed by a linker domain at amino acid 301 to amino acid 431 of SEQ ID NO:2; SEQ ID NO:5 and a CARD at amino acid 432 to amino acid 540 of SEQ ID NO:2; SEQ ID NO:6.
Two forms of CARD-4 exist in the cell, a long form, CARD-4L, and a short form, CARD-4S. The cDNA of CARD-4L described below (SEQ ID NO:7) has a 2859 nucleotide open reading frame (nucleotides 245-3103 of SEQ ID NO:7; SEQ ID NO:9) which encodes a 953 amino acid protein (SEQ ID NO:8). CARD-4L protein possesses a CARD domain (amino acids 15-114; SEQ ID NO:10). CARD-4L is also predicted to have a nucleotide binding domain which extends from about amino acid 198 to about amino acid 397 of SEQ ID NO:8; SEQ ID NO:11, a Walker Box xe2x80x9cAxe2x80x9d, which extends from about amino acid 202 to about amino acid 209 of SEQ ID NO:8; SEQ ID NO:12, a Walker Box xe2x80x9cBxe2x80x9d, which extends from about amino acid 280 to about amino acid 284, of SEQ ID NO:8; SEQ ID NO:13, a kinase 3a subdomain, which extends from about amino acid 327 to about amino acid 338 of SEQ ID NO:8; SEQ ID NO:14, and ten Leucine-rich repeats which extend from about amino acid 674 to about amino acid 950 of SEQ ID NO:8. The first Leucine-rich repeat extends from about amino acid 674 to about amino acid 701 of SEQ ID NO:8; SEQ ID NO:15. The second Leucine-rich repeat extends from about amino acid 702 to about amino acid 727 of SEQ ID NO:8; SEQ ID NO:16. The third Leucine-rich repeat extends from about amino acid 728 to about amino acid 754 of SEQ ID NO:8; SEQ ID NO:17. The fourth Leucine-rich repeat extends from about amino acid 755 to about amino acid 782 of SEQ ID NO:8; SEQ ID NO:18. The fifth Leucine-rich repeat extends from about amino acid 783 to about amino acid 810 of SEQ ID NO:8; SEQ ID NO:19. The sixth Leucine-rich repeat extends from about amino acid 811 to about amino acid 838 of SEQ ID NO:8; SEQ ID NO:20. The seventh Leucine-rich repeat extends from about amino acid 839 to about amino acid 866 of SEQ ID NO:8; SEQ ID NO:21. The eighth Leucine-rich repeat extends from about amino acid 867 to about amino acid 894 of SEQ ID NO:8; SEQ ID NO:22. The ninth Leucine-rich repeat extends from about amino acid 895 to about amino acid 922 of SEQ ID NO:8; SEQ ID NO:23 and the tenth leucine-rich repeat extends from about amino acid 923 to about amino acid 950 of SEQ ID NO:8; SEQ ID NO:24.
The partial cDNA of CARD-4S described below (SEQ ID NO:25) has a 1470 nucleotide open reading frame (nucleotides 1-1470 of SEQ ID NO:25; SEQ ID NO:27) which encodes a 490 amino acid protein (SEQ ID NO:26). CARD-4S protein possesses a CARD domain (amino acids 1-74 of SEQ ID NO:26; SEQ ID NO:28). CARD-4S is predicted to have a P-Loop which extends from about amino acid 163 to about amino acid 170 of SEQ ID NO:26; SEQ ID NO:29, and a Walker Box xe2x80x9cBxe2x80x9d which extends form about amino acid 241 to about amino acid 245 of SEQ ID NO:26; SEQ ID NO:30.
Like other proteins containing a CARD domain, both CARD-3 and CARD-4L/S are expected to participate in the network of interactions that lead to caspase activity. Human CARD-4L is expected to play a functional role in caspase activation similar to that of Apaf-1 (Zou et al., Cell, 90:405-413, 1997). For example, upon acitivation, CARD-4L might bind a nucleotide, thus allowing CARD-4L to bind and activate a CARD-containing caspase via a CARD-CARD interaction, leading to apoptotic death of the cell. Accordingly, CARD-3 and CARD-4 molecules are useful as modulating agents in regulating a variety of cellular processes including cell growth and cell death. In one aspect, this invention provides isolated nucleic acid molecules encoding CARD-3 or CARD-4 proteins or biologically active portions thereof, as well as nucleic acid fragments suitable as primers or hybridization probes for the detection of CARD-3 or CARD-4 encoding nucleic acids.
The invention encompasses methods of diagnosing and treating patients who are suffering from a disorder associated with an abnormal level or rate (undesirably high or undesirably low) of apoptotic cell death, abnormal activity of the Fas/APO-1 receptor complex, abnormal activity of the TNF receptor complex, or abnormal activity of a caspase by administering a compound that modulates the expression of CARD-3 or CARD-4L/S (at the DNA, mRNA or protein level, e.g., by altering mRNA splicing) or by altering the activity of CARD-3 or CARD-4L/S. Examples of such compounds include small molecules, antisense nucleic acid molecules, ribozymes, and polypeptides.
Certain disorders are associated with an increased number of surviving cells, which are produced and continue to survive or proliferate when apoptosis is inhibited. These disorders include cancer (particularly follicular lymphomas, carcinomas associated with mutations in p53, and hormone-dependent tumors such as breast cancer, prostate cancer, and ovarian cancer), autoimmune disorders (such as systemic lupus erythematosis, immune-mediated glomerulonephritis), and viral infections (such as those caused by herpesviruses, poxviruses, and adenoviruses).
Failure to remove autoimmune cells that arise during development or that develop as a result of somatic mutation during an immune response can result in autoimmune disease. One of the molecules that plays a critical role in regulating cell death in lymphocytes is the cell surface receptor for Fas.
Populations of cells are often depleted in the event of viral infection, with perhaps the most dramatic example being the cell depletion caused by the human immunodeficiency virus (HIV). Surprisingly, most T cells that die during HIV infections do not appear to be infected with HIV. Although a number of explanations have been proposed, recent evidence suggests that stimulation of the CD4 receptor results in the enhanced susceptibility of uninfected T cells to undergo apoptosis.
A wide variety of neurological diseases are characterized by the gradual loss of specific sets of neurons. Such disorders include Alzheimer""s disease, Parkinson""s disease, amyotrophic lateral sclerosis (ALS) retinitis pigmentosa, spinal muscular atrophy, and various forms of cerebellar degeneration. The cell loss in these diseases does not induce an inflammatory response, and apoptosis appears to be the mechanism of cell death.
In addition, a number of hematologic diseases are associated with a decreased production of blood cells. These disorders include anemia associated with chronic disease, aplastic anemia, chronic neutropenia, and the myelodysplastic syndromes. Disorders of blood cell production, such as myelodysplastic syndrome and some forms of aplastic anemia, are associated with increased apoptotic cell death within the bone marrow. These disorders could result from the activation of genes that promote apoptosis, acquired deficiencies in stromal cells or hematopoietic survival factors, or the direct effects of toxins and mediators of immune responses.
Two common disorders associated with cell death are myocardial infarctions and stroke. In both disorders, cells within the central area of ischemia, which is produced in the event of acute loss of blood flow, appear to die rapidly as a result of necrosis. However, outside the central ischemic zone, cells die over a more protracted time period and morphologically appear to die by apoptosis.
The invention features a nucleic acid molecule which is at least 45% (or 55%, 65%, 75%, 85%, 95%, or 98%) identical to the nucleotide sequence shown in SEQ ID NO:1, SEQ ID NO:3, SEQ ID NO:7, SEQ ID NO:9, SEQ ID:25, SEQ ID NO:27, the nucleotide sequence of the cDNA insert of the plasmid deposited with ATCC as Accession Number (the xe2x80x9ccDNA of ATCC 203037xe2x80x9d), the nucleotide sequence of the cDNA insert of the plasmid deposited with ATCC as Accession Number (the xe2x80x9ccDNA of ATCC 203037xe2x80x9d), the nucleotide sequence of the cDNA insert of the plasmid deposited with ATCC as Accession Number (the xe2x80x9ccDNA of ATCC 203037xe2x80x9d), or a complement thereof.
The invention features a nucleic acid molecule which includes a fragment of at least 150 (300, 325, 350, 375, 400, 425, 450, 500, 550, 600, 650, 700, 800, 900, 1000, 1300, 1600 or 1931) nucleotides of the nucleotide sequence shown in SEQ ID NO:1, or SEQ ID NO:3, or the nucleotide sequence of the cDNA ATCC 203037, or a complement thereof.
The invention also features a nucleic acid molecule which includes a fragment of at least 150 (350, 400, 450, 500, 550, 600, 650, 700, 800, 900, 1000, 1300, 1600, 1900, 2100, 2400, 2700, 3000, or 3382) nucleotides of the nucleotide sequence shown in SEQ ID NO:7, or SEQ ID NO:9, or the nucleotide sequence of the cDNA ATCC 203035, or a complement thereof.
Also within the invention is a nucleic acid molecule which includes a fragment of at least 150 (350, 400, 450, 500, 550, 600, 650, 700, 800, 900, 1000, 1300, 1600, 1900, 2100, 2400, 2700, and 3080) nucleotides of the nucleotide sequence shown in SEQ ID NO:25, or SEQ ID NO:27, or the nucleotide sequence of the cDNA ATCC 2030306, or a complement thereof.
The invention features a nucleic acid molecule which includes a nucleotide sequence encoding a protein having an amino acid sequence that is at least 45% (or 55%, 65%, 75%, 85%, 95%, or 98%) identical to the amino acid sequence of SEQ ID NO:2, SEQ ID NO:8, SEQ ID NO: 26 or the amino acid sequence encoded by the cDNA of ATCC 203037, the amino acid sequence encoded by the cDNA of ATCC 203037, or the amino acid sequence encoded by the cDNA of ATCC 203036.
In a preferred embodiment, a CARD-3 nucleic acid molecule has the nucleotide sequence shown in SEQ ID NO:1, or SEQ ID NO:3, or the nucleotide sequence of the cDNA of ATCC 203037. In another preferred embodiment, a CARD-4L nucleic acid molecule has the nucleotide sequence shown in SEQ ID NO:7, or SEQ ID NO:9, or the nucleotide sequence of the cDNA of ATCC 203037. In yet another preferred embodiment, a CARD-4S nucleic acid molecule has the nucleotide sequence shown in SEQ ID NO:25, or SEQ ID NO:27, or the nucleotide sequence of the cDNA of ATCC 203036.
Also within the invention is a nucleic acid molecule which encodes a fragment of a polypeptide having the amino acid sequence of SEQ ID NO:2 or SEQ ID NO:8 or SEQ ID NO:26, the fragment including at least 15 (25, 30, 50, 100, 150, 300, 400 or 540, 600, 700, 800, 953) contiguous amino acids of SEQ ID NO:2 or SEQ ID NO:8 or SEQ ID NO:26 or the polypeptide encoded by the cDNA of ATCC Accession Number 203037, or the polypeptide encoded by the cDNA of ATCC Accession Number 203036, or the polypeptide encoded by the cDNA of ATCC Accession Number 203037.
The invention includes a nucleic acid molecule which encodes a naturally occurring allelic variant of a polypeptide comprising the amino acid sequence of SEQ ID NO:2 or an amino acid sequence encoded by the cDNA of ATCC Accession Number 203037, wherein the nucleic acid molecule hybridizes to a nucleic acid molecule comprising SEQ ID NO:1 or SEQ ID NO:3 under stringent conditions. The invention also includes a nucleic acid molecule which encodes a naturally occurring allelic variant of a polypeptide comprising the amino acid sequence of SEQ ID NO:8 or an amino acid sequence encoded by the cDNA of ATCC Accession Number 203035, wherein the nucleic acid molecule hybridizes to a nucleic acid molecule comprising SEQ ID NO:7 or SEQ ID NO:9 under stringent conditions.
The invention also includes a nucleic acid molecule which encodes a naturally occurring allelic variant of a polypeptide comprising the amino acid sequence of SEQ ID NO:26 or an amino acid sequence encoded by the cDNA of ATCC Accession Number 203036 wherein the nucleic acid molecule hybridizes to a nucleic acid molecule comprising SEQ ID NO:25 or SEQ ID NO:27 under stringent conditions.
Also within the invention are: an isolated CARD-3 protein having an amino acid sequence that is at least about 65%, preferably 75%, 85%, 95%, or 98% identical to the amino acid sequence of SEQ ID NO:2; an isolated CARD-3 protein having an amino acid sequence that is at least about 85%, 95%, or 98% identical to the kinase domain of SEQ ID NO:2 (e.g., about amino acid residues 1 to 300 of SEQ ID NO:2; SEQ ID NO:4); and an isolated CARD-3 protein having an amino acid sequence that is at least about 85%, 95%, or 98% identical to the linker domain of SEQ ID NO:2 (e.g., about amino acid residues 301 to 431 of SEQ ID NO:2; SEQ ID NO:5); an isolated CARD-3 protein having an amino acid sequence that is at least about 85%, 95%, or 98% identical to the CARD domain of SEQ ID NO:2 (e.g., about amino acid residues 432 to 540 of SEQ ID NO:2; SEQ ID NO:6); an isolated CARD-4L protein having an amino acid sequence that is at least about 65%, preferably 75%, 85%, 95%, or 98% identical to the amino acid sequence of SEQ ID NO:8; an isolated CARD-4L protein having an amino acid sequence that is at least about 85%, 95%, or 98% identical to the CARD domain of SEQ ID NO:8 (e.g., about amino acid residues 15 to 114 of SEQ ID NO:8; SEQ ID NO:10); an isolated CARD-4L protein having an amino acid sequence that is at least about 85%, 95%, or 98% identical to the nucleotide binding domain of SEQ ID NO:8 (e.g., about amino acid residues 198 to 397 of SEQ ID NO:8; SEQ ID NO:11; an isolated CARD-4L protein having an amino acid sequence that is at least about 85%, 95%, or 98% identical to a kinase 3a subdomain of SEQ ID NO:8 (e.g., about amino acid residues 327 to 338 of SEQ ID NO:8; SEQ ID NO:14); an isolated CARD-4L protein having an amino acid sequence that is at least about 85%, 95%, or 98% identical to the Leucine-rich repeats of SEQ ID NO:8 (e.g., about amino acid residues 674 to 701 of SEQ ID NO:8; SEQ ID NO:15; from amino acid 702 to amino acid 727 of SEQ ID NO:8; SEQ ID NO:16; which extends from amino acid 728 to amino acid 754 SEQ ID NO:8; SEQ ID NO:17; from amino acid 755 to amino acid 782 of SEQ ID NO:8; SEQ ID NO:18; from amino acid 783 to amino acid 810 of SEQ ID NO:8; SEQ ID NO:19; from amino acid 811 to amino acid 838 of SEQ ID NO:8; SEQ ID NO:20 from amino acid 839 to amino acid 866 of SEQ ID NO:8; SEQ ID NO:21; from amino acid 867 to amino acid 894 of SEQ ID NO:8; SEQ ID NO:22; from amino acid 895 to amino acid 922 of SEQ ID NO:8; SEQ ID NO:23; and from amino acid 923 to amino acid 950 of SEQ ID NO:8; SEQ ID NO:24); an isolated CARD-4S protein having an amino acid sequence that is at least about 65%, preferably 75%, 85%, 95%, or 98% identical to the amino acid sequence of SEQ ID NO:26; an isolated CARD-4S protein having an amino acid sequence that is at least about 85%, 95%, or 98% identical to the CARD domain of SEQ ID NO:26 (e.g., about amino acid residues 1 to 74 of SEQ ID NO:26; SEQ ID NO:28).
Also within the invention are: an isolated CARD-3 protein which is encoded by a nucleic acid molecule having a nucleotide sequence that is at least about 65%, preferably 75%, 85%, or 95% identical to SEQ ID NO:3 or the cDNA of ATCC 203037; an isolated CARD-3 protein which is encoded by a nucleic acid molecule having a nucleotide sequence at least about 65% preferably 75%, 85%, or 95% identical to the kinase domain encoding portion of SEQ ID NO:1 (e.g., about nucleotides 213 to 1113 of SEQ ID NO:1); an isolated CARD-3 protein which is encoded by a nucleic acid molecule having a nucleotide sequence at least about 65% preferably 75%, 85%, or 95% identical the linker domain encoding portion of SEQ ID NO:1 (e.g., about nucleotides 1114 to 1506 of SEQ ID NO:1); and an isolated CARD-3 protein which is encoded by a nucleic acid molecule having a nucleotide sequence at least about 65% preferably 75%, 85%, or 95% identical the CARD domain encoding portion of SEQ ID NO:1 (e.g., about nucleotides 1507 to 1833 of SEQ ID NO:1); and an isolated CARD-3 protein which is encoded by a nucleic acid molecule having a nucleotide sequence which hybridizes under stringent hybridization conditions to a nucleic acid molecule having the nucleotide sequence of SEQ ID NO:3 or the non-coding strand of the cDNA of ATCC 203037.
Also within the invention are: an isolated CARD-4L protein which is encoded by a nucleic acid molecule having a nucleotide sequence that is at least about 65%, preferably 75%, 85%, or 95% identical to SEQ ID NO:9 or the cDNA of ATCC 203036; an isolated CARD-4L protein which is encoded by a nucleic acid molecule having a nucleotide sequence at least about 65% preferably 75%, 85%, or 95% identical the CARD domain encoding portion of SEQ ID NO:7 (e.g., about nucleotides 287 to 586 of SEQ ID NO:7); an isolated CARD-4L protein which is encoded by a nucleic acid molecule having a nucleotide sequence at least about 65% preferably 75%, 85%, or 95% identical the nucleotide binding domain encoding portion of SEQ ID NO:7 (e.g., about nucleotides 836 to 1436 of SEQ ID NO:7); an isolated CARD-4L protein which is encoded by a nucleic acid molecule having a kinase 3a subdomain at least about 65% preferably 75%, 85%, or 95% identical the nucleotide binding domain encoding portion of SEQ ID NO:7 (e.g., about nucleotides 1223 to 1258 of SEQ ID NO:7); an isolated CARD-4L protein which is encoded by a nucleic acid molecule having a nucleotide sequence at least about 65% preferably 75%, 85%, or 95% identical the Leucine-rich repeats encoding portion of SEQ ID NO:7 (e.g., about nucleotides 2264 to 2347 of SEQ ID NO:7; about nucleotides 2348 to 2425 of SEQ ID NO:7; about nucleotides 2426 to 2506 of SEQ ID NO:7; about nucleotides 2507 to 2590 of SEQ ID NO:7; about nucleotides 2591 to 2674 of SEQ ID NO:7; about nucleotides 2675 to 2758 of SEQ ID NO:7; about nucleotides 2759 to 2842 of SEQ ID NO:7; about nucleotides 2843 to 2926 of SEQ ID NO:7; about nucleotides 2927 to 3010 of SEQ ID NO:7; about nucleotides 3011 to 3094 of SEQ ID NO:7; and an isolated CARD-4L protein which is encoded by a nucleic acid molecule having a nucleotide sequence which hybridizes under stringent hybridization conditions to a nucleic acid molecule having the nucleotide sequence of SEQ ID NO:9 or the non-coding strand of the cDNA of ATCC 203035.
Also within the invention are: an isolated CARD-4S protein which is encoded by a nucleic acid molecule having a nucleotide sequence that is at least about 65%, preferably 75%, 85%, or 95% identical to SEQ ID NO:27 or the cDNA of ATCC 203036; an isolated CARD-3 protein which is encoded by a nucleic acid molecule having a nucleotide sequence at least about 65% preferably 75%, 85%, or 95% identical the CARD domain encoding portion of SEQ ID NO:25 (e.g., about nucleotides 1 to 222 of SEQ ID NO:25); an isolated CARD-3 protein which is encoded by a nucleic acid molecule having a nucleotide sequence at least about 65% preferably 75%, 85%, or 95% identical the P-Loop encoding portion of SEQ ID NO:25 (e.g., about nucleotides 485 to 510 of SEQ ID NO:25).
Also within the invention is a polypeptide which is a naturally occurring allelic variant of a polypeptide that includes the amino acid sequence of SEQ ID NO:2 or an amino acid sequence encoded by the cDNA insert of the plasmid deposited with ATCC as Accession Number 203037, wherein the polypeptide is encoded by a nucleic acid molecule which hybridizes to a nucleic acid molecule comprising SEQ ID NO:1 or SEQ ID NO:3 under stringent conditions.
Also within the invention is a polypeptide which is a naturally occurring allelic variant of a polypeptide that includes the amino acid sequence of SEQ ID NO:8 or an amino acid sequence encoded by the cDNA insert of the plasmid deposited with ATCC as Accession Number 203037, wherein the polypeptide is encoded by a nucleic acid molecule which hybridizes to a nucleic acid molecule comprising SEQ ID NO:7 or SEQ ID NO:9 under stringent conditions.
Also within the invention is a polypeptide which is a naturally occurring allelic variant of a polypeptide that includes the amino acid sequence of SEQ ID NO:26 or an amino acid sequence encoded by the cDNA insert of the plasmid deposited with ATCC as Accession Number 203036, wherein the polypeptide is encoded by a nucleic acid molecule which hybridizes to a nucleic acid molecule comprising SEQ ID NO:25 or SEQ ID NO:27 under stringent conditions.
Another embodiment of the invention features CARD-3 or CARD-4L/S nucleic acid molecules which specifically detect CARD-3 or CARD-4L/S nucleic acid molecules, relative to nucleic acid molecules encoding other members of the CARD superfamily. For example, in one embodiment, a CARD-4L nucleic acid molecule hybridizes under stringent conditions to a nucleic acid molecule comprising the nucleotide sequence of SEQ ID NO:7, SEQ ID NO:9, or the cDNA of ATCC 203035, or a complement thereof. In another embodiment, the CARD-4L nucleic acid molecule is at least 300 (350, 400, 450, 500, 550, 600, 650, 700, 800, 900, 1000, 1300, 1600, 1900, 2100, 2400, 2700, 3000, or 3382) nucleotides in length and hybridizes under stringent conditions to a nucleic acid molecule comprising the nucleotide sequence shown in SEQ ID NO:7, SEQ ID NO:9, the cDNA of ATCC 203035, or a complement thereof. In another embodiment, an isolated CARD-4L nucleic acid molecule comprises nucleotides 287 to 586 of SEQ ID NO:7, encoding the CARD domain of CARD-4L, or a complement thereof. In yet another embodiment, the invention provides an isolated nucleic acid molecule which is antisense to the coding strand of a CARD-4L nucleic acid.
Another aspect of the invention provides a vector, e.g., a recombinant expression vector, comprising a CARD-3 or a CARD-4L/S nucleic acid molecule of the invention. In another embodiment the invention provides a host cell containing such a vector. The invention also provides a method for producing CARD-3 or CARD-4L/S protein by culturing, in a suitable medium, a host cell of the invention containing a recombinant expression vector such that a CARD-3 or CARD-4L/S protein is produced.
Another aspect of this invention features isolated or recombinant CARD-3 or CARD-4L/S proteins and polypeptides. Preferred CARD-3 or CARD-4L/S proteins and polypeptides possess at least one biological activity possessed by naturally occurring human CARD-3 or CARD-4L/S, e.g., (1) the ability to form protein:protein interactions with proteins in the apoptotic signalling pathway; (2) the ability to form CARD-CARD interactions with proteins in the apoptotic signaling pathway; (3) the ability to bind the CARD-3 or CARD-4L/S ligand; (4) the ability to bind to an intracellular target; and (5) the ability to bind to caspases. Other activities include: (1) modulation of cellular proliferation, (2) modulation of cellular differentiation and (3) modulation of cellular death.
The CARD-3 or CARD-4L/S proteins of the present invention, or biologically active portions thereof, can be operatively linked to a non-CARD-3 or non-CARD-4L/S polypeptide (e.g., heterologous amino acid sequences) to form CARD-3 or CARD-4L/S fusion proteins, respectively. The invention further features antibodies that specifically bind CARD-3 or CARD-4L/S proteins, such as monoclonal or polyclonal antibodies. In addition, the CARD-3 or CARD-4L/S proteins or biologically active portions thereof can be incorporated into pharmaceutical compositions, which optionally include pharmaceutically acceptable carriers.
In another aspect, the present invention provides a method for detecting the presence of CARD-3 or CARD-4L/S activity or expression in a biological sample by contacting the biological sample with an agent capable of detecting an indicator of CARD-3 or CARD-4L/S activity such that the presence of CARD-3 or CARD-4L/S activity is detected in the biological sample.
In another aspect, the invention provides a method for modulating CARD-3 or CARD-4L/S activity comprising contacting a cell with an agent that modulates (inhibits or stimulates) CARD-3 or CARD-4L/S activity or expression such that CARD-3 or CARD-4L/S activity or expression in the cell is modulated. In one embodiment, the agent is an antibody that specifically binds to CARD-3 or CARD-4L/S protein. In another embodiment, the agent modulates expression of CARD-3 or CARD-4L/S by modulating transcription of a CARD-3 or CARD-4L/S gene, splicing of a CARD-3 or CARD-4L/S mRNA, or translation of a CARD-3 or CARD-4L/S mRNA. In yet another embodiment, the agent is a nucleic acid molecule having a nucleotide sequence that is antisense to the coding strand of the CARD-3 or CARD-4L/S mRNA or the CARD-3 or CARD-4L/S gene.
In one embodiment, the methods of the present invention are used to treat a subject having a disorder characterized by aberrant CARD-3 or CARD-4L/S protein or nucleic acid expression or activity by administering an agent which is a CARD-3 or CARD-4L/S modulator to the subject. In one embodiment, the CARD-3 or CARD-4L/S modulator is a CARD-3 or CARD-4L/S protein. In another embodiment the CARD-3 or CARD-4L/S modulator is a CARD-3 or CARD-4L/S nucleic acid molecule. In other embodiments, the CARD-3 or CARD-4L/S modulator is a peptide, peptidomimetic, or other small molecule.
The present invention also provides a diagnostic assay for identifying the presence or absence of a genetic lesion or mutation characterized by at least one of: (i) aberrant modification or mutation of a gene encoding a CARD-3 or CARD-4L/S protein; (ii) mis-regulation of a gene encoding a CARD-3 or CARD-4L/S protein; and (iii) aberrant post-translational modification of a CARD-3 or CARD-4L/S protein, wherein a wild-type form of the gene encodes a protein with a CARD-3 or CARD-4L/S activity.
In another aspect, the invention provides a method for identifying a compound that binds to or modulates the activity of a CARD-3 or CARD-4L/S protein. In general, such methods entail measuring a biological activity of a CARD-3 or CARD-4L/S protein in the presence and absence of a test compound and identifying those compounds which alter the activity of the CARD-3 or CARD-4L/S protein.
The invention also features methods for identifying a compound which modulates the expression of CARD-3 or CARD-4L/S by measuring the expression of CARD-3 or CARD-4L/S in the presence and absence of a compound.
Other features and advantages of the invention will be apparent from the following detailed description and claims.